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Chemphyschem : a European Journal of... Apr 2020Pathologies associated with calcified tissue, such as osteoporosis, demand in vivo and/or in situ spectroscopic analysis to assess the role of chemical substitutions...
Pathologies associated with calcified tissue, such as osteoporosis, demand in vivo and/or in situ spectroscopic analysis to assess the role of chemical substitutions in the inorganic component. High energy X-ray or NMR spectroscopies are impractical or damaging in biomedical conditions. Low energy spectroscopies, such as IR and Raman techniques, are often the best alternative. In apatite biominerals, the vibrational signatures of the phosphate group are generally used as fingerprint of the materials although they provide only limited information. Here, we have used first principles calculations to unravel the complexity of the complete vibrational spectra of apatites. We determined the spectroscopic features of all the phonon modes of fluoroapatite, hydroxy-apatite, and carbonated fluoroapatite beyond the analysis of the phosphate groups, focusing on the effect of local corrections induced by the crystalline environment and the specific mineral composition. This provides a clear and unique reference to discriminate structural and chemical variations in biominerals, opening the way to a widespread application of non-invasive spectroscopies for in vivo diagnostics, and biomedical analysis.
Topics: Apatites; Biocompatible Materials; Models, Molecular; Spectrum Analysis, Raman
PubMed: 32107826
DOI: 10.1002/cphc.202000016 -
Clinical Oral Investigations Oct 2022Evaluate the ability of current ion-releasing materials to remineralise bacteria-driven artificial caries lesions.
OBJECTIVES
Evaluate the ability of current ion-releasing materials to remineralise bacteria-driven artificial caries lesions.
MATERIALS AND METHODS
Standardised class I cavities were obtained in 60 extracted human molars. Specimens underwent a microbiological cariogenic protocol (28 days) to generate artificial caries lesions and then were randomly divided into four restorative groups: adhesive + composite (negative control); glass ionomer cement (GIC); calcium silicate cement (MTA); and resin-modified calcium silicate cement (RMTA). Microhardness analysis (ΔKHN) was performed on 40 specimens (10/group, t = 30 days, 45 days, 60 days in artificial saliva, AS). Micro-CT scans were acquired (3/group, t = 0 days, 30 days, and 90 days in AS). Confocal microscopy was employed for interfacial ultra-morphology analysis (2/group, t = 0 days and 60 days in AS). Additional specimens were prepared and processed for scanning electron microscopy (SEM) and FTIR (n = 3/group + control) to analyse the ability of the tested materials to induce apatite formation on totally demineralised dentine discs (60 days in AS). Statistical analyses were performed with a significance level of 5%.
RESULTS
Adhesive + composite specimens showed the lowest ΔKHN values and the presence of gaps at the interface when assessed through micro-CT even after storage in AS. Conversely, all the tested ion-releasing materials presented an increase in ΔKHN after storage (p < 0.05), while MTA best reduced the demineralised artificial carious lesions gap at the interface. MTA and RMTA also showed apatite deposition on totally demineralised dentine surfaces (SEM and FTIR).
CONCLUSIONS
All tested ion-releasing materials expressed mineral precipitation in demineralised dentine. Additionally, calcium silicate-based materials induced apatite precipitation and hardness recovery of artificial carious dentine lesions over time.
CLINICAL RELEVANCE
Current ion-releasing materials can induce remineralisation of carious dentine. MTA shows enhanced ability of nucleation/precipitation of hydroxyapatite compared to RMTA and GIC, which may be more appropriate to recover severe mineral-depleted dentine.
Topics: Humans; Apatites; Calcium Compounds; Dental Caries; Dentin; Glass Ionomer Cements; Hydroxyapatites; Materials Testing; Minerals; Resin Cements; Saliva, Artificial; Silicates
PubMed: 35670863
DOI: 10.1007/s00784-022-04569-9 -
Journal of Biomaterials Applications Aug 2022Bone-like apatite coating fabricated by biomineralization process is a facile way for surface modification of porous scaffolds to improve interfacial behaviors and thus...
Bone-like apatite coating fabricated by biomineralization process is a facile way for surface modification of porous scaffolds to improve interfacial behaviors and thus facilitate cell attachment, proliferation, and differentiation for bone tissue engineering. In this study, a Sr-containing calcium phosphate solution was made and used to construct a thick layer of Sr-doped bone-like apatite on the surface of 3D printed scaffolds via biomineralization process. Importantly, Sr-doped bone-like apatite could form and fully cover the 3D printed scaffolds surface in hours. The characterization results indicated that Sr ions successfully replaced Ca ions in bone-like apatite and the molar ratio of Sr/(Ca+Sr) was up to 8.2%. Furthermore, the Sr-doped apatite coating increased the compressive strength and Young's modulus of composite scaffolds. The compatibility and bioactivity of mineralized scaffolds were evaluated by cell attachment, proliferation, and differentiation of MC3T3-E1 cells. It was found that Sr-doped apatite coating could gradually release Sr ions and further promote cell attachment, proliferation rate, and the expression of alkaline phosphatase activity and osteogenic related genes, such as collagen type I (Col I), Runt-related transcription factor 2 (Runx-2), osteopontin, and osterix. Therefore, the Sr-doped apatite coating fabricated by this facile and rapid biomineralization process offers a new strategy to modify 3D printed porous scaffolds with significantly improved mechanical and biological properties for bone tissue engineering applications.
Topics: Apatites; Biocompatible Materials; Ions; Printing, Three-Dimensional; Tissue Scaffolds
PubMed: 35400209
DOI: 10.1177/08853282221087107 -
The International Journal of Artificial... May 2022Contamination of large grit sandblasting and acid-etching (SLA) with hydrocarbons make the surface hydrophobic and influence its bioactivity. Preservation in dHO...
INTRODUCTION
Contamination of large grit sandblasting and acid-etching (SLA) with hydrocarbons make the surface hydrophobic and influence its bioactivity. Preservation in dHO (modified SLA, modSLA) and ultraviolet (UV) irradiation were proven to be effective in decreasing hydrocarbon contamination and keeping the SLA surface hydrophilic.
AIMS
The aim of this study was to detect the in vitro bioactivity of SLA, modSLA and UV-SLA surfaces.
DESIGN
The SBF model was used to compare the bone-like apatite forming ability.
SETTING
The experiment was conducted at Southern Medical University.
MATERIALS AND METHODS
The quantity of apatite was assessed by SEM and weighed on an electronic balance. The elemental composition and crystal phase were assessed by EDS and XRD analysis, respectively.
RESULTS
The sediments that completely covered the modSLA and UV-SLA surfaces after 4 weeks of soaking reached 3.23 ± 0.35 mg and 2.13 ± 0.95 mg, respectively. They were eight- and five-fold than that on the SLA surface (0.43 ± 0.15 mg) with statistical significance ( < 0.05 and < 0.01, respectively). EDS and XRD tests recognized the sediments on the modSLA and UV-SLA surfaces as apatite with similar elemental compositions, Ca/P ratios and crystal phases.
DISCUSSION
Hydrophilicity and abundant hydroxyl groups drive modSLA and UV-SLA surfaces to absorb more Ca to accelerate the formation of apatite.
CONCLUSION
SLA preservation in dHO and UV irradiation were recognized as trustworthy methods to acquire greater bioactivity of the SLA surface.
Topics: Apatites; Humans; Hydrophobic and Hydrophilic Interactions; Surface Properties; Titanium
PubMed: 35499230
DOI: 10.1177/03913988221088617 -
Dental Materials : Official Publication... Sep 2020In the context of minimally invasive dentistry and tissue conservation, bioactive products are valuable. The aim of this review was to identify, clarify, and classify... (Review)
Review
OBJECTIVE
In the context of minimally invasive dentistry and tissue conservation, bioactive products are valuable. The aim of this review was to identify, clarify, and classify the methodologies used to quantify the bioactive glasses bioactivity.
METHODS
Specific search strategies were performed in electronic databases: PubMed, Embase, Cochrane Library, and Scopus. Papers were selected after a review of their title, abstract, and full text. The following data were then examined for final selection: BAG investigated, objectives, criteria, methods, and outcomes.
RESULTS
Sixty-one studies published from 2001 to 2019, were included. The bioactivity of BAG can be evaluated in vitro in contact with solutions, enamel, dentin, or cells. Other studies have conducted in vivo evaluation by BAG contact with dentin and dental pulp. Studies have used various analysis techniques: evaluation of apatite with or without characterization or assessment of mechanical properties. Reprecipitation mechanisms and pulp cell stimulation are treated together through the term 'bioactivity'.
SIGNIFICANCE
Based on these results, we suggested a classification of methodologies for a better understanding of the bioactive properties of BAG. According to all in vitro studies, BAG appear to be bioactive materials. No consensus has been reached on the results of in vivo studies, and no comparison has been conducted between protocols to assess the bioactivity of other bioactive competitor products.
Topics: Apatites; Dental Enamel; Glass
PubMed: 32605848
DOI: 10.1016/j.dental.2020.03.020 -
ACS Biomaterials Science & Engineering Apr 2023A novel approach for the production of a bioinspired dentine replacement material is introduced. An apatite-gelatin nanocomposite material was cross-linked with various...
A novel approach for the production of a bioinspired dentine replacement material is introduced. An apatite-gelatin nanocomposite material was cross-linked with various cross-linkers. These nanocomposites have a high resemblance to mammalian dentine regarding its composition and properties. A precipitation reaction was used to produce apatite-gelatin nanocomposites as starting materials. Cross-linking of the gelatin has to be performed to produce dentine-like and thus tough and robust apatite-gelatin nanocomposites. Therefore, the efficacy of various protein cross-linkers was tested, and the resulting materials were characterized by scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, and EXAFS as well as CHNS analysis and tested for their mechanical performance using Vickers hardness measurements as well as for their dissolution stability in EDTA. Especially glutaraldehyde, proanthocyanidins, and transglutaminase gave promising results with hardness values of up to 63 HV0.2. To further improve the material properties, we combined the effective cross-linker transglutaminase with casein, which led to an improved interconnection between the single nanocomposite platelets. By doing so, a cross-linked composite was obtained, which shows even higher hardness values than does human dentine, at 76 HV. The combination of apatite-gelatin nanocomposites with an effective cross-linker resulted in a bioinspired material with composition and properties close to those of human dentine.
Topics: Humans; Animals; Gelatin; Apatites; Nanocomposites; Transglutaminases; Dentin; Mammals
PubMed: 34962771
DOI: 10.1021/acsbiomaterials.1c01071 -
Journal of Environmental Quality Jan 2018Concentrations of apatite phosphorus (P) have been shown to be greater in the soils of agricultural and disturbed watersheds than in soils of forested watersheds. This...
Concentrations of apatite phosphorus (P) have been shown to be greater in the soils of agricultural and disturbed watersheds than in soils of forested watersheds. This observation suggests that changes in the relative concentration of apatite P in the sedimentary record of lakes might be a useful marker for land use changes in the watershed where sediments are dominated by allochthonous loading. To determine if P export in streams is indicative of soil P in the watershed, we measured the export of total, particulate, and apatite P in first-order streams draining four forested and four agricultural watersheds in western Pennsylvania. Streams draining agricultural watersheds exported significantly more total suspended solids (TSS) and more total, particulate, soluble, and apatite P, particularly during periods of high discharge, than did streams draining forested watersheds. Total suspended solids exported from forested watersheds contained similar amounts of apatite P (μg apatite P g TSS), as did agricultural watersheds in spite of lower soil concentrations. However, since agricultural watershed exported almost four times the mass of TSS, the net export of apatite P was greater than from forested streams. These results confirm the increased apatite P export from agricultural watersheds and suggest that inferences drawn from the profiles of apatite P in the sedimentary record of lakes may reliably indicate historical disturbances in watersheds caused by agriculture or other erosional events.
Topics: Agriculture; Apatites; Environmental Monitoring; Pennsylvania; Phosphorus; Rivers; Water Movements
PubMed: 29415108
DOI: 10.2134/jeq2017.06.0227 -
International Journal of Nanomedicine 2016Although biomimetic apatite coating is a promising way to provide titanium with osteoconductivity, the efficiency and quality of deposition is often poor. Most titanium...
BACKGROUND
Although biomimetic apatite coating is a promising way to provide titanium with osteoconductivity, the efficiency and quality of deposition is often poor. Most titanium implants have microscale surface morphology, and an addition of nanoscale features while preserving the micromorphology may provide further biological benefit. Here, we examined the effect of ultraviolet (UV) light treatment of titanium, or photofunctionalization, on the efficacy of biomimetic apatite deposition on titanium and its biological capability.
METHODS AND RESULTS
Micro-roughed titanium disks were prepared by acid-etching with sulfuric acid. Micro-roughened disks with or without photofunctionalization (20-minute exposure to UV light) were immersed in simulated body fluid (SBF) for 1 or 5 days. Photofunctionalized titanium disks were superhydrophilic and did not form surface air bubbles when immersed in SBF, whereas non-photofunctionalized disks were hydrophobic and largely covered with air bubbles during immersion. An apatite-related signal was observed by X-ray diffraction on photofunctionalized titanium after 1 day of SBF immersion, which was equivalent to the one observed after 5 days of immersion of control titanium. Scanning electron microscopy revealed nodular apatite deposition in the valleys and at the inclines of micro-roughened structures without affecting the existing micro-configuration. Micro-roughened titanium and apatite-deposited titanium surfaces had similar roughness values. The attachment, spreading, settling, proliferation, and alkaline phosphate activity of bone marrow-derived osteoblasts were promoted on apatite-coated titanium with photofunctionalization.
CONCLUSION
UV-photofunctionalization of titanium enabled faster deposition of nanoscale biomimetic apatite, resulting in the improved biological capability compared to the similarly prepared apatite-deposited titanium without photofunctionalization. Photofunctionalization-assisted biomimetic apatite deposition may be a novel method to effectively enhance micro-roughened titanium surfaces without altering their microscale morphology.
Topics: Animals; Apatites; Apoptosis; Biomimetics; Cell Adhesion; Cell Movement; Cell Proliferation; Cells, Cultured; Hydrophobic and Hydrophilic Interactions; Male; Microscopy, Electron, Scanning; Nanotechnology; Osteoblasts; Rats; Rats, Sprague-Dawley; Surface Properties; Titanium; Ultraviolet Rays; X-Ray Diffraction
PubMed: 26834469
DOI: 10.2147/IJN.S95249 -
Dental Materials : Official Publication... Jan 2018Biodentine™ is a novel tricalcium silicate based material used both as a coronal dentine replacement and in pulp therapy. Its multiple use in sealing perforations,...
UNLABELLED
Biodentine™ is a novel tricalcium silicate based material used both as a coronal dentine replacement and in pulp therapy. Its multiple use in sealing perforations, pulp capping and as a temporary restoration arises from its ability to promote dentine formation and to confer an excellent marginal seal. However, there is still room for improvement of this cement as it lacks the anticariogenic effect typically conferred by fluoride ion release as seen in glass ionomer cement based dental materials. Therefore, this study was conducted to investigate the impact of bioactive glass addition to Biodentine™.
OBJECTIVE
was to compare the apatite formation capacity, specificity of the apatite type formed and fluoride ion release by Biodentine™ cements that have been modified by three different compositions of bioactive glasses.
METHODS
High fluoride, high strontium and high fluoride plus strontium containing bioactive glasses were synthesized, incorporated into Biodentine™ powder and four types of cements prepared. These cements were immersed in phosphate buffered saline solution and incubated for a period of 3 and 24h, 3, 7 and 14 days. Fourier transform infra-red spectroscopy, X-ray diffraction, magic angle spinning nuclear magnetic resonance and fluoride ion release studies were performed.
RESULTS
Bioactive glass addition to Biodentine™ led to pronounced formation of apatite. Where the bioactive glass contained fluoride, fluorapatite and fluoride ion release were demonstrated.
SIGNIFICANCE
Eliciting fluorapatite formation and fluoride ion release from Biodentine™ is an important development as fluoride is known to have antibacterial and anticariogenic effects.
Topics: Apatites; Biocompatible Materials; Calcium Compounds; Ceramics; Compressive Strength; Dental Cements; Fluorides; Magnetic Resonance Spectroscopy; Materials Testing; Silicates; Spectroscopy, Fourier Transform Infrared; Strontium; X-Ray Diffraction
PubMed: 29042078
DOI: 10.1016/j.dental.2017.10.005 -
Environmental Science and Pollution... Aug 2022In this research, the influence of application mode (capping and amendment) on the control of cadmium (Cd) liberation from sediment by apatite/calcite mixture and its...
In this research, the influence of application mode (capping and amendment) on the control of cadmium (Cd) liberation from sediment by apatite/calcite mixture and its phosphorus release risk were investigated. The results showed that calcite addition had a limited effect on the speciation of Cd in sediment, but apatite addition had a significant impact on the fractionation of Cd in sediment. Apatite amendment could effectively immobilize the most readily mobilized Cd by transferring the acid-soluble fraction to the reducible and residual fractions. Apatite addition also could effectively reduce the concentration of toxicity characteristic leaching procedure (TCLP)-leachable Cd in sediment, and apatite had a much higher reduction efficiency of TCLP-leachable Cd than calcite. Apatite/calcite mixture capping could reduce the risk of Cd liberation from sediment into the overlying water, and the controlling efficiency of apatite/calcite mixture capping was higher than that of apatite/calcite mixture amendment. The effect of apatite/calcite mixture addition on the concentration of reactive soluble phosphorus (SRP) in the overlying water was limited. The introduction of calcite into the apatite capping layer could lower the risk of phosphorus release from apatite to the overlying water as compared to single apatite capping. However, the apatite/calcite mixture capping layer still had a relatively high risk of phosphorus liberation into the overlying water. Results of this work suggest that apatite/calcite mixture has a high potential to be used as a capping material to control Cd release from sediment from the perspective of controlling efficiency and application convenience.
Topics: Apatites; Cadmium; Calcium Carbonate; Geologic Sediments; Phosphorus; Water; Water Pollutants, Chemical
PubMed: 35396681
DOI: 10.1007/s11356-022-20113-4